Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligan...Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.展开更多
The selective oxidation of organic sulfides is a pivotal step in the preparation of sulfoxides that can act as synthetic intermediates when preparing fine chemicals,bioactive molecules,and asymmetric catalysis ligands...The selective oxidation of organic sulfides is a pivotal step in the preparation of sulfoxides that can act as synthetic intermediates when preparing fine chemicals,bioactive molecules,and asymmetric catalysis ligands.To construct high-performance heterogeneous catalysts for sulfide-sulfoxide transformations,herein,we designed and synthesized a supramolecular porous catalyst based onε-Keggin polyoxometalates(POMs),TBA_(2)H_(2)[Zn_(4)(im)(Him)_(2)][ε-PMo_(8)VMo_(4)VIO_(40)]·3H_(2)O(1,Him=1H-imidazole).Single-crystal X-ray diffraction analysis indicates that the porous framework of 1 can be obtained via the supramolecular stacking of one-dimensional helical chains alternately linked by Zn_(4)-ε-Keggin clusters and Him ligands.During the selective oxidation of methyl phenyl sulfide to methyl phenyl sulfoxide(MPSO),compound 1 achieved a>99%yield toward MPSO and 90.3%oxidant utilization efficiency within 10 min.The corresponding turnover frequency(TOF),expressing catalytic activity,was up to 1200 h^(-1).The catalyst also demonstrated extensive substrate tolerance during catalysis,and the corresponding yields of sulfoxides were satisfactory when only 1.2 equivalents of oxidant were used.Besides this,1 can also effectively degrade a sulfur mustard simulant(2-chloroethyl ethyl sulfide)to the nontoxic product 2-chloroethyl ethyl sulfoxide within 10 min at room temperature,with an oxidant utilization efficiency of up to 94.5%.Importantly,the excellent catalytic activity of compound 1 was also proven via comparison with an analogous 3D compound 2(TOF=800 h^(-1)at full MPS conversion),TBAH_(2)[K(Him)(im)][Zn_(4)(Him)(Hip)][ε-PMo_(8)VMo_(4)VIO_(40)](Hip=4-(1H-imidazol-2-yl)-pyridine),which was covalently assembled from one-dimensional Zn_(4)-ε-Keggin POM chains and metal-organic units.Moreover,the truly heterogeneous nature of 1 and 2 was confirmed via cycling and hot-filtration experiments,and their structural stability was verified based on Fourier-transform infrared spectra and powder X-ray diffractometry(PXRD)patterns.展开更多
基金the Academy of Finland(decision 317903,I.O.K.,Flagship Programme,Photonics Research and Innovation PREIN,decision 320166)the Russian Science Foundation(grant 19-73-20055,J.R.S.,photophysical studies)is gratefully acknowledged.
文摘Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.
基金supported by the National Natural Science Foundation of China(21371027,20901013)the Natural Science Foundation of Liaoning Province(2015020232)the Fundamental Research Funds for the Central Universities(DUT19LK01,DUT15LN18).
文摘The selective oxidation of organic sulfides is a pivotal step in the preparation of sulfoxides that can act as synthetic intermediates when preparing fine chemicals,bioactive molecules,and asymmetric catalysis ligands.To construct high-performance heterogeneous catalysts for sulfide-sulfoxide transformations,herein,we designed and synthesized a supramolecular porous catalyst based onε-Keggin polyoxometalates(POMs),TBA_(2)H_(2)[Zn_(4)(im)(Him)_(2)][ε-PMo_(8)VMo_(4)VIO_(40)]·3H_(2)O(1,Him=1H-imidazole).Single-crystal X-ray diffraction analysis indicates that the porous framework of 1 can be obtained via the supramolecular stacking of one-dimensional helical chains alternately linked by Zn_(4)-ε-Keggin clusters and Him ligands.During the selective oxidation of methyl phenyl sulfide to methyl phenyl sulfoxide(MPSO),compound 1 achieved a>99%yield toward MPSO and 90.3%oxidant utilization efficiency within 10 min.The corresponding turnover frequency(TOF),expressing catalytic activity,was up to 1200 h^(-1).The catalyst also demonstrated extensive substrate tolerance during catalysis,and the corresponding yields of sulfoxides were satisfactory when only 1.2 equivalents of oxidant were used.Besides this,1 can also effectively degrade a sulfur mustard simulant(2-chloroethyl ethyl sulfide)to the nontoxic product 2-chloroethyl ethyl sulfoxide within 10 min at room temperature,with an oxidant utilization efficiency of up to 94.5%.Importantly,the excellent catalytic activity of compound 1 was also proven via comparison with an analogous 3D compound 2(TOF=800 h^(-1)at full MPS conversion),TBAH_(2)[K(Him)(im)][Zn_(4)(Him)(Hip)][ε-PMo_(8)VMo_(4)VIO_(40)](Hip=4-(1H-imidazol-2-yl)-pyridine),which was covalently assembled from one-dimensional Zn_(4)-ε-Keggin POM chains and metal-organic units.Moreover,the truly heterogeneous nature of 1 and 2 was confirmed via cycling and hot-filtration experiments,and their structural stability was verified based on Fourier-transform infrared spectra and powder X-ray diffractometry(PXRD)patterns.
